The nation’s weather

Wet weather over the Southeast began to spread northeastward on Sunday, while a chance of severe showers and thunderstorms continued for parts of the Northern High Plains.

A trough of low pressure sliding through the Northern U.S triggered active weather from the Midwest through parts of the Intermountain West as it pushed a warm front eastward and a cold front extended behind the system. This system kicked up showers and thunderstorms from the Great Lakes through the Northern Rockies, while scattered showers and thunderstorms formed to the south of the stalled associated front reaching into the Four Corners. Severe storms in the Northern High Plains had the potential to produce strong winds and large hail.

Meanwhile, as this system slid eastward across the North, a stationary front reached across the Upper Great Lakes northeastward into Maine. While a ridge of high pressure over the Atlantic Ocean maintained warm and moist flow from the Gulf of Mexico, showers and thunderstorms persisted from the Great Lakes and parts of the Ohio Valley into the Northeast. The Storm Prediction Center issued a slight risk of severe storm development from parts of central Pennsylvania into southern New England. Storms in these areas had the potential to produce locally damaging wind gusts and hail in addition to heavy rainfall. Scattered showers and thunderstorms with areas and periods of heavy rainfall also continued from the Gulf Coasts through the Southeast into the central and southern Appalachians. A variety of Flood Warnings continued along the central and eastern Gulf Coasts, while a variety of Flood Watches and Flash Flood Watches continued in the southern and central Appalachians.

Elsewhere in the East, extreme heat continued for areas of the southern New England coast as highs climbed into the 90s and heat index values reached the century mark. Heat Advisories and Excessive Heat Warnings continued for the region through the day.

Out West, the Pacific Northwest and California continued to cool on Sunday, while the Desert Southwest experienced yet another hot day with highs above 100 degrees.

Temperatures in the Lower 48 states Sunday have ranged from a morning low of 37 degrees at Stanley, Idaho to a midday high of 109 degrees at Needles, Calif.